Description
This error message appears, when you try to execute an ALTER TABLE SWITCH command for which source and target table do have a different number of columns.

Consequences
The T-SQL statement can be parsed, but causes the error at runtime.

Resolution
Error of the Severity Level 16 are generated by the user and can be fixed by the SQL Server user. The statement can not be executed this way. Source and target table must a have an identical number of columns.